<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    * {
        margin: 0;
        padding: 0;
    }

    /* 将容器宽度和高度充满整个网页 */
    html,
    body {
        width: 100%;
        height: 100%;
    }

    body {
        background-color: pink;
        display: flex;
        flex-direction: row;
        align-items: center;
        justify-content: center;
    }

    .heart {
        width: 200px;
        height: 200px;
        background-color: red;
        position: relative;
        transform: rotate(45deg);
        animation: heartbit 1s alternate infinite;
        box-shadow: 0 0 30px red;
    }

    .heart::before {
        content: "";
        width: 200px;
        height: 100px;
        background-color: red;
        position: absolute;
        left: 0;
        top: -99px;
        border-radius: 100px 100px 0 0;
        box-shadow: 0 0 30px red;

    }
    .heart::after {
        content: "";
        width: 100px;
        height: 200px;
        background-color: red;
        position: absolute;
        left: -99px;
        top: 0;
        border-radius: 100px 0 0 100px;
        box-shadow: 0 0 30px red;
    }

    @keyframes heartbit{
        0%{
            transform: rotate(45deg) scale(0.6);
        }
        100%{
            transform: rotate(45deg) scale(1.4);
        }
    }
</style>

<body>
    <div class="heart"></div>

</body>

</html>